The present invention relates to refrigeration systems, and in particular to a heater for a door that controls air flow between two compartments of the refrigeration system.
Refrigeration systems may include an insulated freezer compartment and an insulated refrigeration compartment. A refrigeration unit including a compressor, condenser, and evaporator may be utilized to cool the freezer compartment. A powered door (“air door”) selectively opens and closes to control air flow from the freezer compartment to the refrigerator compartment. The air door thereby controls the flow of cold air from the freezer compartment into the refrigerator compartment to control the temperature in the refrigerator compartment. A thermostat in the refrigeration compartment may be set to a target temperature, and a temperature sensor in the refrigeration compartment may monitor the actual temperature in the refrigeration compartment. In the event the temperature in the refrigeration compartment is above the target temperature, the door to the freezer compartment is opened, thereby allowing cold air from the freezer compartment to flow into the refrigeration compartment until the temperature drops below the target temperature value.
Ice or frost buildup at the door may, however, interfere with opening and closing of the air door. Heaters have been developed to melt the ice and frost from air doors. However, heaters generally require energy for operation, and known door heater arrangements may provide less than optimum efficiency.